As can be seen by reference to the following U.S. Pat. Nos. 4,534,427; and 4,708,214; the prior art is replete with myriad and diverse borehole drilling arrangements which employ abrasive fluids to effect the drilling of the strata in the vicinity of the high pressure nozzle.
While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, these prior art arrangements have been uniformly deficient with regard to in site mixing of the abrasive and high pressure water spray at the nozzle outlet; as well as providing a mixing manifold immediately downstream of the high pressure outlet; wherein the mixing manifold is designed and configured to cooperate with, yet move independently of the pipe string from which it is suspended and to direct an abrasive jet toward the sidewall of a borehole.
As a consequence of the foregoing situation, there has existed a longstanding need for a rugged cutting head fluid manifold construction that will both cooperate with and serve to protect a conventional pipe string arrangement and to direct an abrasive jet toward the sidewall of a borehole and the provision of such a construction is a stated objective of the present invention.